"The concept of the candidates is really central to the final season of the show," Cuse tells TVGuide.com. "Jacob is dead so that leaves a significant problem for the people on the island. Who is destined to be the person who is protecting this place?"

"One of the big questions of this show is: Why were these people brought to this island?" Lindelof adds. "At least now we have some sense — if Jacob is responsible for bringing them there — that it has something to do with the fact that he's been observing them for quite some time. We now have information that he had this lighthouse, that he was able to see these people, look into their lives. For some reason, he chose them. We'll find out what that reason is in the coming weeks."

And how does that reason relate to the "sideways" world, the alternate universe in which Oceanic 815 landed safely in Los Angeles? We've seen some things have changed significantly there (um, Jack has a son), while for others, salient details remain the same (Locke is still in a wheelchair, even though he also appears to be on speaking terms with the man who we know to have put him there). So who's David's mother and how was Locke paralyzed in this universe? "These are all the right questions," producer Edward Kitsis says. "Those questions that you're picking up on are things that when we made those episodes, we very consciously wanted you to wonder about that," adds producer Adam Horowitz.

While many fans have griped that the sideways story lines have been an unnecessary distraction this season, Lindelof emphasizes that they're very important. "People are saying [they] don't need these stories and all we can say is they're absolutely 100 percent necessary to tell the story of Lost, and hopefully by the end of the season it will be more obvious as to why," he said.

Here's a question that might boggle your mind: If you die in one universe, what happens to your body in other universes? "Charlie and Boone died in the island, but they seem to be alive in the sideways," said Lindelof. "What happens if you die in the sideways? That's an interesting question." Bottom line: Will there be a lot of death this season? "It depends on what your version of a lot is," said Kitsis. "For my mother, one is too many."